Thinking about the song Mary don't you weep (Leadbelly?):

Oh Mary, don't you weep, don't you mourn,
Oh Mary, don't you weep, don't you mourn,
Pharoah's army got drownded, Oh Mary don't you weep.

The verses are Old Testament but Mary is probably the mother of Jesus. In black tradition Moses was the symbol of liberation... I can't quite figure why the song connected the two images.
I imagine the song predated Leadbelly, but I'd like to hear other's speculation on why Mary and the Moses story got mixed up here.
Brad http://www.camasnet.com/~asondahl/bradindex.html